Since an LED element as a semiconductor light-emitting device has a small size, a long life, and excellent power saving performance, LED elements have been widely used as a light source of a display lamp, or the like. In recent years, an LED element having higher brightness has been produced at a relatively low cost, and thus, the use of LED elements as a light source in place of a fluorescent lamp and a light bulb has been considered. When LED elements are used as such a light source, a method has been frequently used in which plural LED elements are arranged on a surface mounting type LED package, that is, a metal substrate (LED mounting substrate) of aluminum or the like, and a reflector (a reflecting body) which reflects light in a predetermined direction is arranged in the vicinity of each LED element to obtain high illuminance.
However, since LED elements give off heat generation during light-emitting, in an LED light device adopting such a method, the reflector is deteriorated due to a rising temperature during light-emitting of the LED elements, and the reflectivity is degraded and brightness is degraded. Thus, the lifetime of the LED element is shortened. Accordingly, heat resistance is required for the reflector.
In addition, it is also required that even when the temperature rises during light-emitting of the LED elements, the reflector is not deteriorated.
Further, the material for forming a reflector is required to have a property of being easily processed into a reflector to increase productivity, that is, high formability, with the above-described properties.
As a reflector resin composition, for example, in PTL 1, there is proposed a light reflecting thermosetting resin composition containing (A) an epoxy resin, (B) a curing agent, (C) a curing catalyst, (D) an inorganic filler, (E) a white pigment, and (F) a coupling agent.
In PTL 2, there is proposed a polyamide composition containing polyamide having cyclohexanedicarboxylic acid units including 50 mol % to 100 mol % of 1,4-cyclohexanedicarboxylic acid units and diamine units including 50 mol % to 100 mol % of aliphatic diamine units having 4 to 18 carbon atoms.
In PTL 3, there is proposed a resin composition made of a fluororesin (A) having carbon-hydrogen bonding and titanium oxide (B).